The purpose of the Cold Spring Harbor Laboratory training program is to train highly qualified postdoctoral fellows with a broad expertise in basic cancer research. The program emphasizes a multi-disciplinary approach which encompasses concepts and state-of-the-art techniques for molecular biology, biochemistry, protein chemistry, protein chemistry, genetics and cell biology. Specific research training is offered in the analysis of the activities of viral and cellular oncogenes and their roles in controlling gene expression, DNA replication, and phenotype of the transformed cell. Each fellow will conduct an independent research program in collaboration with one of the thirty-one senior staff faculty. Trainees will have access to other faculty, who interact extensively for advice, technical help, and collaboration. Faculty members already have an active research program and represent a variety of expertise. The postdoctoral trainees will be encouraged to publish papers and to present data and scientific meetings. Trainees will participate in several in-house seminar series and discussion groups as well as have access to the Laboratory's extensive summer meetings/workshop/postgraduate advanced course program, which runs from March through December. This allows the trainees to communicate with speakers and participating attendees of the meetings and courses. Attendees come from around the world, and there is a free flow of information in an informal atmosphere. The trainees will be highly qualified candidates who have previously obtained a professional doctorate level degree. Postdoctoral candidates are chosen from among the large number of recent Ph.D.'s or M.D.s who apply or come to the attention of the staff. They are promising young scientists who are accepted into the laboratory of one of the senior staff scientists on the faculty. The qualification of prospective trainees must be approved by the Training Grant Faculty Committee. Each trainee has maximum freedom to select a project in conjunction with his or her faculty preceptor. We are seeking to renew our support for eight trainees.